Lump Sum vs DCA Calculator
Compare a lump sum with monthly dollar-cost averaging on historical SPY and QQQ month-end data. For every start month with a full window, see how often the lump sum finished ahead and how wide the ending-value gap was.
Lump sum ending value was higher in 209 of 286 start months (Jan 1993 through Oct 2016).
Ending-value gap by percentile
Lump sum minus DCA, as a percent of the original amount. A positive gap means the lump sum finished higher.
| Percentile | Gap |
|---|---|
| 10th | -11.4% |
| 25th | -1.0% |
| Median | +7.7% |
| 75th | +18.0% |
| 90th | +27.3% |
Lowest ending value
The smallest ending value for each strategy, and the start month that produced it.
Distribution of the gap
Each bar is a count of start months. Bins use the same gap as the table: lump sum minus DCA, as a percent of the amount.
This calculator is an educational scenario tool. It is not investment advice, and it is not a buy or sell recommendation.
Assumptions
- Prices are monthly month-end adjusted closes, with dividends reinvested. The sample is one start month per month-end, not every trading day.
- No taxes, fees, or other trading frictions.
- Uninvested cash earns the annual yield you enter, compounded monthly. The default is 0%, so waiting cash does not grow. Yield stays in cash and is not added to the next equity tranche.
- The lump sum buys at the start month-end. DCA splits the original amount into equal monthly tranches, starting at that same month-end. Ending value is marked at the horizon month-end. A tranche scheduled after that date is still cash. A tranche scheduled on that date is invested at the ending price.
- Past results are not a forecast of future results.
- Data as of 2026-10-30. Source: Yahoo Finance adjusted close.
Keep the comparison with the rest of the plan
The future TickerVal app is being shaped around saved assumptions, portfolio review notes, and tax-aware context.